Outline

Objective

Phenylephrin (Neosinephrin-POS 5%) is an alpha1-agonist that is used regulary to widen the pupil. Application of Neosynephrin 10% eye drops decreased of the diameter of the vessels in the retina (Lanzl. Ith With Vilser W. Kotliar K.E. Berlin 99.DOG 2001). Purpose: Measurement of the retinal microcirculation by Scanning Doppler Flowmetry after local application of Neosinephrin-POSÂ® 5% (Phenylephrin).

Methods

The capillar perfusion of the retina was measured by HRF (Retina Heidelberg Flowmetry). The analyses were carried out with AFFPIA. We evaluated: DC, flow entire, flow average, flow in big vessels, capillaries, capillar+intercapillar area. The number of the measurement points per picture was measured additional and the offset correction parameters a and b were analysed. Persons: 10 healthy persons in the age of year 46Â±13. Study design: We examined the retinal microcirculation before and after local application of Neosinephrin POS 5%. The images of the capillar circulation were made in the same areas of the retina before and 20 minutes after application of one drop Neosynephrin POSÂ® 5% (Phenylephrin) into the right-eye. In 5 subjects we measured the retinal microzirculation after local application of phenylephrin every 10 minutes up to 40 minutes. The contralateral, undropped eye, was regarded as control.

Results

The DC-value, the number of the measurement points and the noise component showed no change within 20 minutes after local application of Phenylephrin. The retinal circulation decreased significantly about -36Â±12% (p=0.005), flow average about -31Â±16% (p=0.005), flow in the capillar+intercapillar area about -31Â±16% (p= 0.005). We observed the strongest effect 20 to 30 minutes after local application of Phenylephrin. After 40 minutes we have observed no normalisation of the retinal circulation.